Forever young?

Can science really help us to delay the effects of ageing? A range of drugs is already available and used by thousands of people. But the real answer may be much simpler, reports Caroline White

As legend has it, the Spanish explorer Ponce de Leon set sail in 1513 to find the island of Bimini, where a fountain, set in gold and silver, reportedly cured illness and granted the drinker eternal youth. The island proved elusive. Instead – and aptly enough – De Leon discovered the coast of the south-eastern United States, or Florida to you and me.

His quest has now become a multi-million-dollar industry. In 2000, "seniors" accounted for almost half of the US specialty supplements market, valued at about $6bn, in an effort to turn back the clock. Next month, in the UK, the book 500 of the Most Important Ways to Stay Younger Longer will swell the expanding anti-ageing library. It joins the proliferation of websites, institutes and treatments that promise to make the growing numbers of those in middle age and beyond look and feel decades younger.

Genes have only a 25 per cent stake in determining how long we live, so the rest is down to us. But is the marketing hype for age-busters justified? Are we just deluded victims of a youth-obsessed culture?

"We can't 'cure' ageing," says Professor Tom Kirkwood, of the Department of Gerontology at Newcastle University, adding that this doesn't mean we can't do anything about it. "But we cherish extraordinarily negative stereotypes of the ageing process. There's a tendency to clutch at anything to prevent it."

Ever since a small US study of older men was undertaken in 1990, hopes have been pinned on synthetic growth hormone. The authors concluded that the hormone's natural wastage over time had a role in the dwindling muscle bulk, skin thinning, and increasing flab seen in ageing. Claims for growth hormone's mood- and memory-enhancing properties, and its positive effects on the immune system and libido, swiftly followed.

Produced by the pituitary gland, growth hormone is essential for the development and maintenance of bone, tissues and organs. But once you hit 30, levels start tailing off by roughly 14 per cent a decade.

Although only licensed to treat stunted growth in the UK, it's widely available over the internet and is familiar to many from unsolicted e-mails promising an "anti-ageing miracle".

There are, of course drawbacks. To begin with, growth hormone must be injected. It also seems to work best in men and when combined with testosterone, suggests a recent study in the Journal of the American Medical Association. Side effects, including glucose intolerance, diabetes and carpal tunnel syndrome also developed in 40 per cent of those in the US study. Other studies have suggested growth hormone can increase the risk of cancer.

Dr Marc Blackman, of the National Center for Complementary and Alternative Medicine at the US National Institutes of Health, says: "We don't know what the optimal therapeutic dose is, or when is the best age to start. The older a person, the more sensitive they are to adverse effects."

Still, the lure of hormonal rejuvenation remains strong. US sales of testosterone skin patches doubled in 2001. An estimated 250,000 men in the US now use them to counter the effects of the andropause, the equivalent of the female menopause.

Men have less testosterone as they age. And lower levels have been associated with cardiovascular disease in both older men and post-menopausal women. Higher levels have been associated with better memory and spatial awareness.

But because levels naturally fluctuate, "normal" values vary enormously, and commercial tests to measure deficiencies are notoriously unreliable. And the signs are that testosterone replacement can trigger blood thickening, and consequently, the risk of strokes. It might also heighten the risk of prostate cancer, the second leading cause of cancer death in men.

"Some deterioration in hormone levels could be beneficial for ageing tissues," suggests Prof Kirkwood. "These are very powerful agents. It's like putting rocket fuel into an old banger."

But vanishing hormones are only part of the ageing story. Cumulative cellular damage is thought to be a major factor in ageing and degenerative disease. However, some researchers think that something as simple and readily available as vitamin and nutritional supplements might be all that's needed. Bruce Ames is professor of Biochemistry and molecular biology at the University of California. He is convinced that common nutritional deficiencies can accelerate ageing, mimicking the cellular DNA damage caused by toxic chemicals and radiation. The recommendations for daily nutrient intake needs to be urgently revised, he says, and tailored to age.

An optimal intake of essential nutrients and metabolites would "tune up" metabolism and substantially increase health at little cost, he says, urging us to take a daily multivitamin "as an insurance policy".

"There's not much acute nutritional deficiency in the West, but a high percentage of the population is low in vitamins and minerals," says Ames, suggesting that up to one in five of us does not eat enough of the 40 essential micronutrients needed to sustain optimal health, including the B vitamins, selenium, zinc and iron.

Thanks to better sanitation, nutrition, and medicine, life expectancy is increasing; by the middle of this century, 20 per cent of the world's population will be 65 and older. But the real issue for ageing research is about the ability to retain physical and mental health into old age, emphasises Dr Blackman.

"Will you be able to walk a distance, get out of a chair, climb stairs, carry shopping? But more and more people want an easy fix, or regard ageing as a disease, instead of it being part of the normal life cycle."

A version of this article appears in the February issue of 'Medicine Today' (www.medicine-today.co.uk). '500 of the Most Important Ways to Stay Younger Longer', by Hazel Courtney, CICO Books, £10.99